Data / Rankings / Population under 18 / Counties in Ohio

Counties in Ohio by population under 18

Holmes County had the highest population under 18 of 88 counties in 2021, at 30.5%. Athens County had the lowest, at 16.1%. The median was 22.3% and the figure for Ohio was 22%. Source: the U.S. Census Bureau.

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Highest30.5Holmes County
Lowest16.1Athens County
Median22.388 counties
Ohio22History

Map of counties, 2021

Adams County: 24.1 %Allen County: 23.3 %Ashland County: 22.4 %Ashtabula County: 21.7 %Athens County: 16.1 %Auglaize County: 23.6 %Belmont County: 19.1 %Brown County: 22.7 %Butler County: 23.4 %Carroll County: 20.9 %Champaign County: 22.4 %Clark County: 22.3 %Clermont County: 22.5 %Clinton County: 22.2 %Columbiana County: 20.2 %Coshocton County: 24.4 %Crawford County: 21.4 %Cuyahoga County: 20.2 %Darke County: 23.7 %Defiance County: 23 %Delaware County: 25.9 %Erie County: 19.7 %Fairfield County: 24.1 %Fayette County: 23.5 %Franklin County: 23 %Fulton County: 23.3 %Gallia County: 23.5 %Geauga County: 22.2 %Greene County: 21 %Guernsey County: 21.7 %Hamilton County: 22.5 %Hancock County: 21.9 %Hardin County: 23.3 %Harrison County: 21.5 %Henry County: 23 %Highland County: 23.9 %Hocking County: 21.7 %Holmes County: 30.5 %Huron County: 23.3 %Jackson County: 23.7 %Jefferson County: 19.5 %Knox County: 23.1 %Lake County: 19.2 %Lawrence County: 22 %Licking County: 22.9 %Logan County: 22.3 %Lorain County: 21.7 %Lucas County: 22.5 %Madison County: 20.7 %Mahoning County: 19.8 %Marion County: 21.1 %Medina County: 21.6 %Meigs County: 21.4 %Mercer County: 25.6 %Miami County: 23.1 %Monroe County: 20.3 %Montgomery County: 21.8 %Morgan County: 20.7 %Morrow County: 22.5 %Muskingum County: 22.7 %Noble County: 18.7 %Ottawa County: 18.1 %Paulding County: 24.2 %Perry County: 23.7 %Pickaway County: 22.5 %Pike County: 24.2 %Portage County: 18.6 %Preble County: 22.4 %Putnam County: 25.4 %Richland County: 21.6 %Ross County: 21.2 %Sandusky County: 21.8 %Scioto County: 21.8 %Seneca County: 21.8 %Shelby County: 24.7 %Stark County: 21.4 %Summit County: 20.7 %Trumbull County: 20.1 %Tuscarawas County: 22.6 %Union County: 25 %Van Wert County: 23.5 %Vinton County: 21.6 %Warren County: 24.2 %Washington County: 19.7 %Wayne County: 24 %Williams County: 21.9 %Wood County: 20.8 %Wyandot County: 22.1 %
  • Under 21
  • 21 to 22
  • 22 to 23
  • 23 to 24
  • 24 and over
%, 2021. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

Holmes County: 30.5 %Holmes County30.5Delaware County: 25.9 %Delaware County25.9Mercer County: 25.6 %Mercer County25.6Putnam County: 25.4 %Putnam County25.4Union County: 25 %Union County25Shelby County: 24.7 %Shelby County24.7Coshocton County: 24.4 %Coshocton County24.4Pike County: 24.2 %Pike County24.2Warren County: 24.2 %Warren County24.2Paulding County: 24.2 %Paulding County24.2Adams County: 24.1 %Adams County24.1Fairfield County: 24.1 %Fairfield County24.1Wayne County: 24 %Wayne County24Highland County: 23.9 %Highland County23.9Perry County: 23.7 %Perry County23.7Darke County: 23.7 %Darke County23.7Jackson County: 23.7 %Jackson County23.7Auglaize County: 23.6 %Auglaize County23.6Gallia County: 23.5 %Gallia County23.5Van Wert County: 23.5 %Van Wert County23.5Fayette County: 23.5 %Fayette County23.5Butler County: 23.4 %Butler County23.4Allen County: 23.3 %Allen County23.3Fulton County: 23.3 %Fulton County23.3Hardin County: 23.3 %Hardin County23.3Huron County: 23.3 %Huron County23.3Knox County: 23.1 %Knox County23.1Miami County: 23.1 %Miami County23.1Henry County: 23 %Henry County23Defiance County: 23 %Defiance County23Franklin County: 23 %Franklin County23Licking County: 22.9 %Licking County22.9Brown County: 22.7 %Brown County22.7Muskingum County: 22.7 %Muskingum County22.7Tuscarawas County: 22.6 %Tuscarawas County22.6Lucas County: 22.5 %Lucas County22.5Morrow County: 22.5 %Morrow County22.5Pickaway County: 22.5 %Pickaway County22.5Clermont County: 22.5 %Clermont County22.5Hamilton County: 22.5 %Hamilton County22.5Holmes County: 30.5 %Holmes County30.5Delaware County: 25.9 %Delaware County25.9Mercer County: 25.6 %Mercer County25.6Putnam County: 25.4 %Putnam County25.4Union County: 25 %Union County25Shelby County: 24.7 %Shelby County24.7Coshocton County: 24.4 %Coshocton County24.4Pike County: 24.2 %Pike County24.2Warren County: 24.2 %Warren County24.2Paulding County: 24.2 %Paulding County24.2Adams County: 24.1 %Adams County24.1Fairfield County: 24.1 %Fairfield County24.1Wayne County: 24 %Wayne County24Highland County: 23.9 %Highland County23.9Perry County: 23.7 %Perry County23.7Darke County: 23.7 %Darke County23.7Jackson County: 23.7 %Jackson County23.7Auglaize County: 23.6 %Auglaize County23.6Gallia County: 23.5 %Gallia County23.5Van Wert County: 23.5 %Van Wert County23.5Fayette County: 23.5 %Fayette County23.5Butler County: 23.4 %Butler County23.4Allen County: 23.3 %Allen County23.3Fulton County: 23.3 %Fulton County23.3Hardin County: 23.3 %Hardin County23.3Huron County: 23.3 %Huron County23.3Knox County: 23.1 %Knox County23.1Miami County: 23.1 %Miami County23.1Henry County: 23 %Henry County23Defiance County: 23 %Defiance County23Franklin County: 23 %Franklin County23Licking County: 22.9 %Licking County22.9Brown County: 22.7 %Brown County22.7Muskingum County: 22.7 %Muskingum County22.7Tuscarawas County: 22.6 %Tuscarawas County22.6Lucas County: 22.5 %Lucas County22.5Morrow County: 22.5 %Morrow County22.5Pickaway County: 22.5 %Pickaway County22.5Clermont County: 22.5 %Clermont County22.5Hamilton County: 22.5 %Hamilton County22.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2021 (%)Change on 2020
1Holmes County30.5-0.2 pts
2Delaware County25.9-0.5 pts
3Mercer County25.6+0.1 pts
4Putnam County25.4-0 pts
5Union County25-0.4 pts
6Shelby County24.7-0.1 pts
7Coshocton County24.4+0.1 pts
8Pike County24.2+0.2 pts
9Warren County24.2-0.3 pts
10Paulding County24.2+0.2 pts
11Adams County24.1+0.1 pts
12Fairfield County24.1-0.1 pts
13Wayne County24-0.1 pts
14Highland County23.9-0 pts
15Perry County23.7-0.1 pts
16Darke County23.7-0 pts
17Jackson County23.7-0.2 pts
18Auglaize County23.6-0.2 pts
19Gallia County23.50 pts
20Van Wert County23.5-0.3 pts
21Fayette County23.50 pts
22Butler County23.40 pts
23Allen County23.3-0.1 pts
24Fulton County23.3-0.2 pts
25Hardin County23.3+0.1 pts
26Huron County23.3-0.2 pts
27Knox County23.1+0.1 pts
28Miami County23.1-0.1 pts
29Henry County23-0.3 pts
30Defiance County23-0 pts
31Franklin County23-0 pts
32Licking County22.9-0.1 pts
33Brown County22.7-0.1 pts
34Muskingum County22.70 pts
35Tuscarawas County22.6-0.3 pts
36Lucas County22.5-0.1 pts
37Morrow County22.5-0.3 pts
38Pickaway County22.5+0.1 pts
39Clermont County22.5-0.3 pts
40Hamilton County22.5-0.1 pts
41Preble County22.4-0.1 pts
42Ashland County22.4-0.1 pts
43Champaign County22.4-0.3 pts
44Clark County22.3-0 pts
45Logan County22.3-0.1 pts
46Geauga County22.2-0.2 pts
47Clinton County22.2-0.1 pts
48Wyandot County22.1-0.2 pts
49Lawrence County22-0 pts
50Williams County21.9-0.4 pts
51Hancock County21.9-0.1 pts
52Sandusky County21.8-0.2 pts
53Scioto County21.8+0.1 pts
54Seneca County21.8-0.1 pts
55Montgomery County21.8-0.1 pts
56Ashtabula County21.7-0.1 pts
57Guernsey County21.7-0 pts
58Hocking County21.7-0.2 pts
59Lorain County21.7-0 pts
60Medina County21.6-0.3 pts
61Richland County21.6-0.1 pts
61Vinton County21.6-0.6 pts
63Harrison County21.5+0.4 pts
64Meigs County21.4+0.1 pts
65Crawford County21.4+0.1 pts
66Stark County21.4-0 pts
67Ross County21.20 pts
68Marion County21.1-0.2 pts
69Greene County21-0.1 pts
70Carroll County20.9-0.1 pts
71Wood County20.8+0.2 pts
72Madison County20.7-0.3 pts
73Morgan County20.7+0.1 pts
74Summit County20.7-0.2 pts
75Monroe County20.3+0.1 pts
76Cuyahoga County20.2-0.1 pts
77Columbiana County20.2-0.1 pts
78Trumbull County20.1+0.1 pts
79Mahoning County19.8-0 pts
80Washington County19.7-0.1 pts
81Erie County19.7-0.2 pts
82Jefferson County19.5-0.1 pts
83Lake County19.2-0.3 pts
84Belmont County19.1-0 pts
85Noble County18.7-0.3 pts
86Portage County18.6+0.2 pts
87Ottawa County18.1-0.2 pts
88Athens County16.1+0.5 pts

Other periods

About this ranking

Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.

Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in Ohio by population under 18, 2021) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Ohio by population under 18, 2021. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in Ohio by population under 18, 2021. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Ohio by population under 18, 2021 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_ohio_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Ohio by population under 18, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Ohio by population under 18, 2021
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/ohio-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -
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Rank Counties in Ohio by population under 18 using official data, and cite the source.
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Questions

Which county has the highest population under 18?

Holmes County, with 30.5% in 2021, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Athens County, with 16.1% in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.

Population under 18: other rankings

Counties in Ohio: more rankings